Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 281609
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
907 AM PDT SAT MAR 28 2015

.SYNOPSIS...
A WEAK UPPER LEVEL TROUGH WILL BRING SOME COOLING TO THE REGION THIS
WEEKEND...ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING COASTAL
LOW CLOUDS AND FOG. MINOR DAY TO DAY CHANGES IN THE WEATHER ARE
EXPECTED MONDAY THROUGH WEDNESDAY...WITH SOME NIGHT THROUGH MORNING
LOW CLOUDS AND FOG IN COASTAL AREAS. TEMPERATURES WILL LIKELY REMAIN
ABOVE NORMAL...ALTHOUGH THERE WILL BE SOME COOLING IN THE MOUNTAINS
AND DESERTS. A WARMING TREND IS EXPECTED AT THE END OF THE WEEK...
ESPECIALLY WEST OF THE MOUNTAINS AS LOW LEVEL FLOW TURNS OFFSHORE.

&&

.SHORT TERM (TODAY-MON)...LOW CLOUDS AND FOG HAVE BECOME WIDESPREAD
ON THE CENTRAL COAST AND IN THE SANTA YNEZ VALLEY...AND CLOUDS WERE
BEGINNING TO PUSH INTO THE SALINAS VALLEY. THE MARINE LAYER DEPTH
WAS AROUND 500 FEET. THERE WAS SOME LOCALLY DENSE FOG N OF PT
CONCEPTION...THOUGH NOT WIDESPREAD ENOUGH TO REQUIRE ADVISORIES. S
OF PT CONCEPTION...SKIES WERE CLEAR...ALTHOUGH SOME PATCHY STRATUS
WAS BEGINNING TO FORM JUST OFF THE COAST OF L.A. COUNTY. EXPECT SOME
CLOUDS TO MOVE INTO COASTAL SECTIONS OF L.A. COUNTY BY DAYBREAK.
SKIES SHOULD CLEAR BY MID OR LATE MORNING IN MOST AREAS.

INCREASING ONSHORE GRADIENTS SHOULD HELP BRING SEVERAL DEGREES OF
COOLING TO THE COASTAL PLAIN AND THE VLYS TODAY. HEIGHTS AND
THICKNESSES WILL REMAIN QUITE HIGH...SO MAX TEMPS WILL STILL BE
WELL ABOVE NORMAL...ESPECIALLY IN THE VLYS WHERE THE MARINE
INFLUENCE WILL BE MINIMAL. IN THE MTNS AND DESERTS...MAX TEMPS MAY
ACTUALLY EDGE UPWARD A DEGREE OR TWO.

A WEAK UPPER TROUGH WILL PUSH INTO THE WEST COAST TONIGHT AND
SUNDAY. STRONG NW WINDS ACROSS THE COASTAL WATERS SHOULD HELP SPIN
UP A GOOD EDDY CIRCULATION TONIGHT. THE WRF INDICATES MORE IN THE
WAY OF LOW CLOUDS AND FOG IN COASTAL SECTIONS OF L.A. COUNTY...WITH
CLOUDS LIKELY SPREADING NWD INTO THE VTU COUNTY COAST...AND POSSIBLY
TO SERN SBA COUNTY. CLOUDS MAY ALSO PUSH INTO THE SAN GABRIEL VLY.
FOR NOW...HAVE GONE WITH A FAIR AMOUNT OF LOW CLOUDS ON THE CENTRAL
COAST...BUT THE LATEST WRF SHOWS SOME LOW LEVEL NELY FLOW...SO
CONFIDENCE IN THAT IS NOT GREAT. SKIES SHOULD BECOME MOSTLY SUNNY BY
LATE MORNING. MAX TEMPS WILL LIKELY BE DOWN A BIT MORE ON
SUNDAY...ESPECIALLY IN THE VLYS. HOWEVER...SLIGHT WARMING IS
POSSIBLE ACROSS PORTIONS OF THE CENTRAL COAST IF LOW LEVEL NE WINDS
DEVELOP.

THE UPPER TROUGH WILL MOVE E OF THE REGION SUNDAY NIGHT/MON...AND A
WEAK UPPER RIDGE WILL BUILD INTO THE REGION. ANOTHER GOOD EDDY CRCLN
SHOULD HELP BRING WIDESPREAD CLOUDS TO COASTAL AREAS S OF PT
CONCEPTION...WITH CLOUDS LIKELY SPREADING INTO THE L.A. COUNTY VLYS.
LOW LEVEL NELY FLOW SHOULD BRING A REDUCTION IN THE LOW CLOUDS TO
THE CENTRAL COAST. SLIGHT RISES IN HEIGHTS/THICKNESSES WILL BE
OFFSET BY INCREASING ONSHORE FLOW IN COASTAL AND VLY AREAS S OF PT
CONCEPTION. OVERALL...EXPECT LITTLE CHANGE IN MAX TEMPS IN MOST
AREAS MON.


.LONG TERM (TUE-FRI)...A BROAD TROUGH WILL MOVE INTO THE W COAST
TUE...AND ONSHORE FLOW WILL INCREASE. THIS SHOULD BRING AN INCREASE
IN NIGHT THROUGH MORNING LOW CLOUDS AND FOG...WITH SOME COOLING
IN MOST AREAS. ANOTHER WEAK UPPER TROUGH WILL SWING INTO THE WEST
COAST ON WED...SO EXPECT MOSTLY MINOR CHANGES IN MAX TEMPS...EXCEPT
POSSIBLY ADDITIONAL COOLING IN THE MTNS AND DESERTS.
HEIGHT/THICKNESSES WILL FALL A BIT MORE THU...BUT THE LOW LEVEL FLOW
WILL TURN MORE NLY. THERE SHOULD BE SOME COOLING IN THE MTNS AND
DESERTS...WHILE MAX TEMPS MAY ACTUALLY RISE A BIT IN COASTAL
AND VLY AREAS. LOW LEVEL FLOW IS FCST TO TURN OFFSHORE THU NIGHT AND
FRI. THIS SHOULD BRING ADDITIONAL WARMING TO AREAS W OF THE
MTNS...WITH LITTLE IF ANY NIGHT THROUGH MORNING LOW CLOUDS AND FOG.

&&

.AVIATION...28/1300Z.


MARINE LAYER AT LAX AT 1305Z WAS 500 FEET DEEP AND THE INVERSION TOP
IS AT 1960 FEET WITH A TEMP OF 23 DEGREES C.

S OF POINT CONCEPTION...MODERATE CONFIDENCE FOR 12Z COASTAL TAFS AND
HIGH CONFIDENCE FOR INLAND TAFS OVER NEXT 24 HOURS. VLIFR CONDS FOR
LAX THROUGH 15Z...OTHERWISE IFR CIGS FOR LGB WHILE OTHER COASTAL
TAFS WILL BE VFR. 40 PERCENT CHANCE FOR KOXR TO GO LIFR BETWEEN
14-16Z THIS MORNING. LOWER CONFIDENCE FOR RETURN OF CIGS THIS
EVENING.

N OF POINT CONCEPTION...MODERATE CONFIDENCE WITH 12Z TAFS. EXPECT
VLIFR TO LIFR CIGS FOR KSBP AND KSMX THROUGH 16Z. 30 PERCENT CHANCE
THAT CIGS WILL IMPOVE BY 15Z. 30 PERCENT CHANCE THAT LIFR CIGS WILL
SCOUR OUT AN HOUR LATER. EXPECT A SIMILAR TIME FOR RETURN OF CIGS
WITH SIMILAR CONDITIONS.

KLAX...MODERATE CONFIDENCE WITH 12Z TAF. EXPECT VLIFR CONDS THROUGH
AT ELAST 15Z. 30 PERCENT CHANCE THIS WILL CONTINUE THROUGH 16Z. CIGS
SHOULD IMPROVE TO MVFR/VFR AFTER 18Z. CIGS SHOULD BE A TAD HIGHER
TONIGHT.

KBUR...HIGH CONFIDENCE WITH 12Z TAF. 30 PERCENT CHANCE FOR MVFR
CONDS FROM 10-12Z EARLY SUN MORNING.


&&

.MARINE...28/900 AM

SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST FROM POINT PIEDRAS
BLANCAS TO POINT SAL 10-60 NM AND FROM POINT SAL TO SAN CLEMENTE
ISLAND THROUGH SUNDAY. THE STRONGEST NORTHWEST WINDS WILL LIKELY
OCCUR THIS AFTERNOON THROUGH EARLY SUNDAY MORNING WITH LOCAL
GUSTS TO 35 KT. THERE IS A CHANCE NORTHWEST WINDS WILL INCREASE TO
GALE FORCE NEXT WEEK TUESDAY FROM POINT PIEDRAS TO SAN NICOLAS
ISLAND INCLUDING THE WEST HALF OF SANTA BARBARA CHANNEL. A MIXED
SWELL IS LIKELY THROUGH THE WEEKEND...WEST-NORTHWEST AT 14
SECONDS...SOUTH SWELL AT 19 SECONDS AND LOCALLY GENERATED NORTHWEST
SWELL AT 8 SECONDS. THE COMBINED SEAS FROM POINT PIEDRAS BLANCAS TO
SAN CLEMENTE ISLAND WILL PEAK 10 TO 12 FEET TONIGHT. THE SHORTER
PERIOD SEAS WILL SUBSIDE SUNDAY THROUGH MONDAY MORNING AND IS
EXPECTED TO REBUILD TUESDAY WHILE A FRESH WEST-NORTHWEST SWELL MIXES
INTO THE COASTAL WATERS TUESDAY. PATCHY DENSE FOG...WITH VSBYS BELOW
1 NM WILL AFFECT AREAS THROUGH THE REMAINDER OF THE MORNIGN AND
AGAIN SUN MORNING.

&&

.BEACHES...A LONG PERIOD SWELL FROM THEN SOUTHERN HEMISPHERE WILL
CONTINUE THROUGH THE REMAINDER OF THE WEEKEND. EXPECT ELEVATED SURF
AND STRONG RIP CURRENTS AND LONGSHORE CURRENTS ON BEACHES ALONG
EXPOSED SOUTH FACING SHORES.

&&


.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...CK/30


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